Re: [PATCH v1 08/15] libvhost-user: Don't zero out memory for memory regions

[Raphael Norwitz]

On Fri, Feb 2, 2024 at 4:56 PM David Hildenbrand <david@redhat.com> wrote:
>
> dev->nregions always covers only valid entries. Stop zeroing out other
> array elements that are unused.
>
> Signed-off-by: David Hildenbrand <david@redhat.com>

Reviewed-by: Raphael Norwitz <raphael@enfabrica.net>

> ---
>  subprojects/libvhost-user/libvhost-user.c | 7 +------
>  1 file changed, 1 insertion(+), 6 deletions(-)
>
> diff --git a/subprojects/libvhost-user/libvhost-user.c 
> b/subprojects/libvhost-user/libvhost-user.c
> index f99c888b48..e1a1b9df88 100644
> --- a/subprojects/libvhost-user/libvhost-user.c
> +++ b/subprojects/libvhost-user/libvhost-user.c
> @@ -888,13 +888,9 @@ vu_rem_mem_reg(VuDev *dev, VhostUserMsg *vmsg) {
>
>              munmap((void *)(uintptr_t)r->mmap_addr, r->size + 
> r->mmap_offset);
>
> -            /*
> -             * Shift all affected entries by 1 to close the hole at index i 
> and
> -             * zero out the last entry.
> -             */
> +            /* Shift all affected entries by 1 to close the hole at index. */
>              memmove(dev->regions + i, dev->regions + i + 1,
>                      sizeof(VuDevRegion) * (dev->nregions - i - 1));
> -            memset(dev->regions + dev->nregions - 1, 0, sizeof(VuDevRegion));
>              DPRINT("Successfully removed a region\n");
>              dev->nregions--;
>              i--;
> @@ -2119,7 +2115,6 @@ vu_init(VuDev *dev,
>          DPRINT("%s: failed to malloc mem regions\n", __func__);
>          return false;
>      }
> -    memset(dev->regions, 0, VHOST_USER_MAX_RAM_SLOTS * 
> sizeof(dev->regions[0]));
>
>      dev->vq = malloc(max_queues * sizeof(dev->vq[0]));
>      if (!dev->vq) {
> --
> 2.43.0
>
>